The physiology, genetics, and distribution of ponderosa pine species vary with changes in elevation and environmental conditions

Research Issue

Collecting data on tree populations as part of a forest indicator and monitoring system is important to confirm models for predicting climate change effects on individual forest stands. Current developments in DNA sequencing methods aid research on plant responses to environmental stress including growth, water usage, and cross interbreeding to form hybrids – and Ponderosa pine species are prime candidates for study.

Our Research

In the desert southwest, significant variations in moisture and temperature occur along steep gradients in elevation. Notably, the endemic ponderosa pine species vary with changes in elevation and the differences in elevation are repeated throughout the ranges of the species. The long-term goal of the study is to provide a foundation for future regional studies of species range limitations by water or temperature stress. This information is vital to further increase our understanding of the movement of tree species within and between climate zones. Our objective is to study genetic variation and constraints on woody plant growth based on habitat preference, primarily water availability. Study sites include three -south facing slopes of the Santa Catalina Mountain range where the species co-exist and are potentially hybridizing. Two of the mountains have experienced fire in the last decade providing tremendous opportunity to study the naturally regenerating seedlings of surviving parental trees.

Expected Outcomes

The research will be valuable to scientists examining the stress response of plant species. In addition, the conclusions will be useful to land managers for the study aims to describe in detail the spatial distribution of the two-pine species. Such knowledge will provide viable options for long-term improvement of reforestation efforts and sustainable management of natural areas in the desert southwest.